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  1. kellys_eye

    Minimum viable precision heating (800F/425C)

    I reckon the key to it will be 'mass' - in terms of larger blocks to maintain a given heat level or a smaller block to give faster control over it! Either way, it's all a matter of compromise and will depend on the end product/process. Control is fairly straightforward both in application and...
  2. kellys_eye

    Submerging Steamer Wand

    No electrical risk but a definite risk to your finances as the energy in those wands is far too small to make a significant difference to water heating using the steam output..... look at the steam cleaners technical spec and if its wattage is less than your electric kettle then factor in the...
  3. kellys_eye

    Problem with finding power switch microcircuit

    Sure it's '5P' and not 'SP'? The potential 'SP' designation is probably to do with the package style. If the 'P' refers to the PENTAWATT package style and given the application it would seem your assumption on the parts numbering is correct.
  4. kellys_eye

    Heathkit GC-1197 Help - Skipping Beat and Chimes are Way Too Low

    Dim digits? Are these the ubiquitous 'filament' seven segment devices? In which case you could potentially raise the supply voltage BUT replacement of the digit itself is the preferred method.
  5. kellys_eye

    Heathkit GC-1197 Help - Skipping Beat and Chimes are Way Too Low

    Your situation isn't helped by a lack of schematic but the notes are generated through diode mixing so they all need testing for leakage. If the issue locates 'around' a couple of IC's then replace or improve the local supply rail suppression capacitors. As with much of vintage electronics...
  6. kellys_eye

    Sharp RT-3388a solenoid/plunger not working

    Do all the physical switches (mechanical) all work? Are they all in their correct operating position? Have the contacts been cleaned? Still can't read the damned schematic! but the solenoid is essentially activated from two inputs at the base of Q804? There re two 10k resistors attached to...
  7. kellys_eye

    Sharp RT-3388a solenoid/plunger not working

    Do you have the 3V regulated supply to the control unit via Q810?(Q819 - still can't see the details - need a clearer schematic) - maybe pin 7 of the control unit? The 'multiple' faults you have mentioned all stem from the output(s) of the control module which won't work without that 3V? supply
  8. kellys_eye

    Sharp RT-3388a solenoid/plunger not working

    The image of the schematic looks to say Q808 - it's very blurred on my screen and could be different! It's the transistor with the collector connected to the coil.
  9. kellys_eye

    Can't find a PCB designer to hire for cool position. Is PCB design completely ignored in schools?

    Advertising by asking for people with advanced skills in using 'xyz PCB design software' might be somewhere to start. It can take many months to familiarise oneself with a modern PCB design package - rules pertaining to the actual boards in respect to the application (high speed data, RF etc)...
  10. kellys_eye

    Chauvet DJ's DMX-RT playback problems

    Clearly you're going to have to 'go in'....... if it's anything like any typical modern electronics it'll revolve around changing dud capacitors on the supply rails (electrolytics). Without resorting to professional test equipment just changing all the 'usual suspects' will be the only real...
  11. kellys_eye

    Reading data from AT21CS01 using an Arduino board

    So many experimenters fail to appreciate the valuable resource that is the manufacturers datasheet! They are often the ONLY way to appreciate the full abilities of any component - they also commonly have hints and tips as well as schematics for common applications.
  12. kellys_eye

    Sharp RT-3388a solenoid/plunger not working

    What about the supply to the solenoid circuitry? Can you activate the solenoid by shorting Q808 collector-emitter?
  13. kellys_eye

    Chauvet DJ's DMX-RT playback problems

    Power supply glitches could be problematic. Any other switching devices nearby/attached? Is the PSU suitably rated etc.
  14. kellys_eye

    esp32 Data lost from computer to micro- controller.

    Can you upload the code at a slower baud rate? or is this a loss of code whilst running it?
  15. kellys_eye

    Identify this resistor?

    ...based on what assumption? It looks perfectly ok and 'damaged' resistors are usually visibly damaged. It should measure 10 ohms and 1% tolerance (if the colours are brown and black - they could be red, in which case this will mean 20 ohms and 2% tolerance). Of course, you may be replacing...
  16. kellys_eye

    portable radio stations

    What make/model? What frequency(ies)? Do you have the appropriate licence(s)? You don't need to 'boost the power' if you have the facilities to make a directional antenna at the operating frequency.
  17. kellys_eye

    off topic problem with fancy smart kegger and gas, fluid cooling system.

    Switch the pump on momentarily and put your finger over one of the pipes. The one that sucks is the one the refrigerant goes in. Generally - if I understand your description - the 'stub' is the gas input and usually pinched off/soldered closed after charging. The compressors in my fridges...
  18. kellys_eye

    Trying to Trick my A/C Unit

    There is always someone who thinks that there's only one solution to every problem - these are often referred to as 'narrow-minded individuals'. When they compound their narrow-mindedness with gratuitous insults to those who give their free time to offer assistance (even if it's wrong, it's...
  19. kellys_eye

    Remote control

    Isn't 38kHz the 'baud rate' at which the data is sent rather than the carrier frequency?
  20. kellys_eye

    Need Help With Relays

    What kind of motors? I doubt they are simple commutated motors - the usual practise is to use either servo motors or stepper motors as some form of feedback is always necessary. Both servo motors and steppers don't use straight DC voltages so relays won't work.
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